In a release the North-West Regional Health Authority confirmed the incident as happening at approximately 2:40 pm yesterday.
The release says preliminary reports indicate that the source was within the kitchen area of the department.
It says as a precautionary measure, three patients from the Intensive Care Unit, which is above the Physiotherapy Department, were relocated to another area.
No one was injured as a result of this incident.
The NWRHA says the Physiotherapy Department will remain closed today to facilitate deep cleaning of the area.
It says outpatients with scheduled appointments will be contacted to reschedule.
The NWRHA in its release thanks the Trinidad and Tobago Fire Services, members of the Trinidad and Tobago Police Service and their staff members for their swift actions during this incident.